/*
 * Copyright (C) 2012 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.io;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.List;

import junit.framework.TestCase;

/**
 * @param <S> the source or sink type
 * @param <T> the data type (byte[] or String)
 * @param <F> the factory type
 * @author Colin Decker
 */
@AndroidIncompatible // Android doesn't understand tests that lack default constructors.
public class SourceSinkTester<S, T, F extends SourceSinkFactory<S, T>> extends TestCase
{

    static final String LOREM_IPSUM =
            "Lorem ipsum dolor sit amet, consectetur adipiscing "
                    + "elit. Cras fringilla elit ac ipsum adipiscing vulputate. Maecenas in lorem nulla, ac "
                    + "sollicitudin quam. Praesent neque elit, sodales quis vestibulum vel, pellentesque nec "
                    + "erat. Proin cursus commodo lacus eget congue. Aliquam erat volutpat. Fusce ut leo sed "
                    + "risus tempor vehicula et a odio. Nam aliquet dolor viverra libero rutrum accumsan "
                    + "quis in augue. Suspendisse id dui in lorem tristique placerat eget vel risus. Sed "
                    + "metus neque, scelerisque in molestie ac, mattis quis lectus. Pellentesque viverra "
                    + "justo commodo quam bibendum ut gravida leo accumsan. Nullam malesuada sagittis diam, "
                    + "quis suscipit mauris euismod vulputate. Pellentesque ultrices tellus sed lorem "
                    + "aliquet pulvinar. Nam lorem nunc, ultrices at auctor non, scelerisque eget turpis. "
                    + "Nullam eget varius erat. Sed a lorem id arcu dictum euismod. Fusce lectus odio, "
                    + "elementum ullamcorper mattis viverra, dictum sit amet lacus.\n"
                    + "\n"
                    + "Nunc quis lacus est. Sed aliquam pretium cursus. Sed eu libero eros. In hac habitasse "
                    + "platea dictumst. Pellentesque molestie, nibh nec iaculis luctus, justo sem lobortis "
                    + "enim, at feugiat leo magna nec libero. Mauris quis odio eget nisl rutrum cursus nec "
                    + "eget augue. Sed nec arcu sem. In hac habitasse platea dictumst.";

    static final ImmutableMap<String, String> TEST_STRINGS =
            ImmutableMap.<String, String>builder()
                    .put("empty", "")
                    .put("1 char", "0")
                    .put("1 word", "hello")
                    .put("2 words", "hello world")
                    .put("\\n line break", "hello\nworld")
                    .put("\\r line break", "hello\rworld")
                    .put("\\r\\n line break", "hello\r\nworld")
                    .put("\\n at EOF", "hello\nworld\n")
                    .put("\\r at EOF", "hello\nworld\r")
                    .put("lorem ipsum", LOREM_IPSUM)
                    .build();

    protected final F factory;
    protected final T data;
    protected final T expected;

    private final String suiteName;
    private final String caseDesc;

    SourceSinkTester(F factory, T data, String suiteName, String caseDesc, Method method)
    {
        super(method.getName());
        this.factory = checkNotNull(factory);
        this.data = checkNotNull(data);
        this.expected = checkNotNull(factory.getExpected(data));
        this.suiteName = checkNotNull(suiteName);
        this.caseDesc = checkNotNull(caseDesc);
    }

    @Override
    public String getName()
    {
        return super.getName() + " [" + suiteName + " [" + caseDesc + "]]";
    }

    protected static ImmutableList<String> getLines(final String string)
    {
        try
        {
            return new CharSource()
            {
                @Override
                public Reader openStream() throws IOException
                {
                    return new StringReader(string);
                }
            }.readLines();
        }
        catch (IOException e)
        {
            throw new AssertionError();
        }
    }

    @Override
    public void tearDown() throws IOException
    {
        factory.tearDown();
    }

    static ImmutableList<Method> getTestMethods(Class<?> testClass)
    {
        List<Method> result = Lists.newArrayList();
        for (Method method : testClass.getDeclaredMethods())
        {
            if (Modifier.isPublic(method.getModifiers())
                    && method.getReturnType() == void.class
                    && method.getParameterTypes().length == 0
                    && method.getName().startsWith("test"))
            {
                result.add(method);
            }
        }
        return ImmutableList.copyOf(result);
    }
}
